Skip to main content

Prevent multiple postbacks in SharePoint 2013


The scenario:  Disabled the button after user’s click event. Prevent user from clicking it several times.

The problem: If the button is disabled, the server side event handler is not fired.

The solution: Set the property UseSubmitBehavior to false.

Explanations

Here is the working code of how to have disabled button after it is clicked:


<asp:Button ID="Button1" runat="server" Text="Do Postback" UseSubmitBehavior="false"  OnClick="Button1_Click" OnClientClick="Validate(this)"  />


       function Validate(thisObj)
       {
           thisObj.disabled = true;
           return true;
       }


If you don't set the property UseSubmitBehavior your code in the handler Button1_Click won’t fire. I spend several hours in debugging it. Hope this save time to somebody.




Comments

Popular posts from this blog

ClientPeoplePicker in SharePoint 2013

Start using SharePoint 2013 I noticed that the way for selecting people or groups is changed.
The new way is simple – just ‘Enter name or email address’ without any icons for ‘Check Names’ or ‘Browse’. I guess that the PeoplePicker is changed but NO. PeoplePicker sitll has the same functionality as before.
There is a new control called ClientPeoplePicker.

How to use it:
1.Add this references

<%@RegisterTagPrefix="wssawc"Namespace="Microsoft.SharePoint.WebControls"Assembly="Microsoft.SharePoint, Version=15.0.0.0, Culture=neutral, PublicKeyToken=71e9bce111e9429c"%>
2.Add the following control declaration


      <wssawc:ClientPeoplePicker Required="true" ValidationEnabled="true" ID="peoplePicker" runat="server" InitialHelpText="<%$Resources:wss,aclinv_PickerIntialHelperText%>" VisibleSuggestions="3" Rows="1" AllowMultipleEntities="false" CssClass

Using SharePoint Attachments' controls with elevated security

The scenario:  Create custom forms for Add/Edit/Delete items to a list which is not accessible by the regular users. The forms should support working with attachments.

The problem: The default SharePoint controls don’t work if the current user doesn’t have access to the list items.

The solution:Use custom code for generating the SharePoint default HTML so the out-of-the-box javascript works correct.

Explanations: 
The scenario occurs when some list need to be hidden form the users. The list has broken security inheritance and users can't navigate directly to it.

Working with its fields requires crating web warts or application pages with appropriate controls on them and server-side code running under elevated privileges. The issue here is that the OOTB (out-of-the-box) controls for Attachments don't work if the user doesn’t have access to the related list item.

The OOTB controls are: AttachmentsField, AttachmentUpload, AttachmentButton. There is a lot of code how to use them so h…

The column name that you entered is already in use or reserved. Choose another name.

The problem: 
You want to create column with a specific name in SharePoint but SharePoint gives you the message "The column name that you entered is already in use or reserved. Choose another name."



Why this is a problem?
Because you need to create custom columns and content types using the default SharePoint interface.
And the business users have to see properly named columns - for example "Description", not "My Description".

Solution:
It is important to know something technical about SharePoint (versions Office 365, 2013, 2010):
 - it supports columns with same Display Names.
 - you can’t have columns with same Internal names

Let’s implement the following common scenario:
You are creating a SharePoint customization and you need the following column:
   Type: Multiple lines of text
   Internal Name: MyProjectDescription
   Display Name: Description

 Here is the correct way to achieve it:
1. Create the column MyProjectDescription.
This will create column with I…